This invention relates, in general, to the testing of semiconductor devices, and more particularly, to an apparatus for testing of packaged semiconductor devices.
In the past, the testing of semiconductor devices packaged in dual inline (DIL) packages, or semiconductor packages similar thereto, has been accomplished by using activated contacts. Activated contacts make electrical contact to the outside of each lead of a packaged semiconductor device. The productivity or throughput of testing products using activated contacts is slow because time is taken up waiting for the contacts to stop moving and make good electrical contact. In addition, activated contacts have long lead lengths which represent non-transmission lines. Thus, because of the losses which take place, the activated contacts are only good for DC testing, but not AC testing. In order to make an activated contact a transmission line, a ground plane must be added to the activated contacts. This reduces the losses and allows AC testing to take place. It is also very difficult to provide Kelvin contacts to an activated contact apparatus, because the contacts are large compared to the package leads. Kelvin contacts provide for better accuracy in measurement, therefore, inaccuracies in measurement must be tolerated when using activated contacts. Lastly, activated contacts use about 30 grams of pressure when testing each part, thus the contacts, which are typically made of a beryllium/copper alloy, must be replaced frequently due to wear.
Other methods of testing semiconductor devices in SOIC (Small Outline Integrated Circuit) packages are not directly compatible with the testing of dual inline packages. The leads of an SOIC are bent in a "J" configuration, while the leads of a dual inline package are straight. Thus, a method of making contact to the bottom surface of the leads of an SOIC can not be used for dual inline packages or other similar packages.
Accordingly, it is an object of the present invention to provide an apparatus for testing packaged semiconductor devices with an improved productivity.
Another object of the present invention is to provide an apparatus for testing packaged semiconductor devices which has shorter contact lead lengths which allows for AC and DC testing.
An additional object of the present invention is to provide an apparatus for testing packaged semiconductor devices which improves accuracy by providing a Kelvin contact.
A further object of the present invention is to provide an apparatus for testing semiconductor devices which provides for less wear.